Serious damage caused by hard blows and extreme twisting frequently occurs to an athlete's knee in various contact sports. This is particularly true of the game of American football. Despite the frequency and severity of such accidents, most technological progress in recent years has been in post-injury protective devices and in surgical procedures. Devices or equipment designed to prevent such injury are generally not available or inadequate under severe circumstances.
The steel hinge which straps to the leg above and below the knee is well known. However, its use has been largely limited to two situations. One is for use by those who have suffered injury, but not so severly that surgery cannot wait until after remaining games in the season are played. The other is for use by those whose surgery is recent enough that cautionary protection is warranted. The reasons for these limits are that such devices are quite restrictive in terms of the amount of knee flex permitted and the degree of flexibility remaining while in place. Additionally, the steel knee hinge is heavy and it allows almost no lateral bending.
Protection against torn knee ligaments and kneecap damage is, therefore, unavailable in a practical sense to the athlete who has not as yet suffered such an injury or has, hopefully, recovered from one. In either instance, the quality of the athlets's performance will suffer due to his knowledge of the pain involved and the negative effect on his career resulting from such knee injury.